Removable tooth points have been used on excavating buckets and other earth moving equipment for many years. In that time several varying arrangements for retaining a tooth in place have emerged. Typically these designs attach tooth points to adapters, which in turn are attached to an excavating bucket or are otherwise secured to the earth moving device. The tooth points engage the earth to loosen it and allow the bucket to scoop it up for removal.
With large-scale excavating equipment, such as draglines, the tooth points of the bucket are subjected to substantial forces and frictional wear. Thus, tooth points wear down quickly, slowing excavation work because they cannot dig into the soil effectively, requiring greater force to do the same work and subjecting the entire excavating machine to greater stresses. In addition, without the loosening effect of the teeth, the bucket may suffer damage because of its engagement with unloosened material.
If the tooth points are replaced frequently, the excavating machine operates more efficiently. However, replacing tooth points can be a labor-intensive job, requiring costly down time for the excavating machine. Prior tooth point designs have attempted to reduce the amount of labor required to replace the points while still securely locking the tooth point to the adapter during operation. However, such designs have met with small degrees of success.
Some prior designs have used a locking pin extending vertically through the tooth point. However, in such designs, the heads of the pin are exposed to the main body of earth going into the bucket and to the earth below so that rocks often hit the heads of the pin causing deformation and dirt wedges between the pin and the receiving hole. Consequently, the pin is difficult to remove and much time is required to replace such tooth points.
Other designs have used pins that enter horizontally. However, such pins are generally difficult to replace because of the small space between teeth. Some designs have tried to remedy the problem by using two pins in the design. However, such designs still require the user to pound both pins through the width of the tooth point before removing the tooth. This is difficult because of the limited space between the teeth of the bucket.
Main body pins in large rigging parts have also been difficult to remove. A typical rigging part, such as a clevis pin must be easily removable and must be able to withstand the wear and tear associated with such parts. Past clevis parts have typically consisted of an "U"-shaped eye portion, hubs located at the end of each upright leg of the "U", and a main body pin extending between the hubs. Typically these main body pins have been secured either by a spool and wedge configuration or by welding a plate over the head of the pin. In the spool and wedge configuration, a pin is driven into a hole in the main body pin and is held in place by a compression fit. The main body pin is difficult to remove with either of these configurations. The compression-fit pins in the spool and wedge configuration have been so difficult to drive out that users have often resorted to cutting the main body pin out with a torch. The welded plate configuration also requires a torch or grinder to cut the plate off and allow the main body pin to be removed. In either case, the pins are very difficult to secure and release from the eye portion of the clevis. Similar problems have occurred with main body pins in other rigging parts such as shackles and pick-up links.